Charged lepton mixing and oscillations from neutrino mixing in the early Universe

We explore charged lepton mixing and oscillations as a consequence of neutrino mixing in the early Universe, assuming chemical and thermal equilibrium of neutrinos as \emph{mass eigenstates} at high temperature before flavor equalization. The upper bounds on the neutrino asymmetry parameters from CMB and BBN without oscillations, combined with the fit to the solar and KamLAND data for the neutrino mixing angle, suggest that for the two generation case there is resonant \emph{charged lepton} mixing in the temperature range $T \sim 5-10 \mathrm{GeV}$. Mixing angles and time scales for charged lepton oscillations are studied to lowest order in the weak charged current interaction